Standing wave electron beam accelerators have found wide usage in medical accelerators where the high energy electron beam is employed to generate x-rays for therapeutic and diagnostic purposes. Electron beam generated by an electron beam accelerator can also be used directly or indirectly to kill infectious pests, to sterilize objects, to change physical properties of objects, and to perform testing and inspection of objects, such as containers for storing radioactive material, and concrete structures.
Electron beam accelerators are powered by power generators. Generally, power generated by generators may be controlled at the source, such that energy can be delivered to accelerators in a certain manner. In some applications, it may be desirable to have power from a generator that varies between at least two power levels, such that an accelerator can generate energy pulses that vary between at least two different energy levels. However, existing power systems may not be able to accomplish these objectives. Also, existing power generators may not be able to provide generated power such that energy delivered to the accelerators can vary quickly, e.g., in the order of microseconds, between at least two energy levels, which may be desirable in certain radiation systems.
Further, in existing systems, radio-frequency (RF) power provided by a power generator to an accelerator may be reflected back to the power generator. In many applications, it is desirable that such reflected power be controlled or minimized (or at least reduced), so that a frequency of a power generator will be “pulled” to the accelerator frequency, resulting in a stable operation of the power generator and the accelerator. If the reflected power is not controlled, the frequency of the power generator will be pulled away from that of the accelerator, resulting in difficulty of getting the power generator to operate at a frequency required by the accelerator.